Chalcopyrite Solid Solution Research Articles

Synthesis and Transport Properties of ZnSnP2-yAsy Chalcopyrite Solid Solutions.

This work focuses on the synthesis and properties of quaternary ZnSnP2-yAsy chalcopyrite solid solutions. Full miscibility of the solid solution is achieved using ball milling followed by hot press sintering. The measured electrical conductivity increases substantially with As substitution from 0.03 S cm-1 for ZnSnP2 to 10.3 S cm-1 for ZnSnAs2 at 715 K. Band gaps calculated from the activation energies show a steady decrease with increasing As concentration from 1.4 eV for ZnSnP2 to 0.7 eV for ZnSnAs2. The Seebeck coefficient decreases significantly with As substitution from nearly 1000 μV K-1 for ZnSnP2 to -100 μV K-1 for ZnSnAs2 at 650 K. Thermal conductivity is decreased for the solid solutions due to alloy phonon scattering, compared to the end members with y = 0 and y = 2, with the y = 0.5 and y = 1.0 samples exhibiting the lowest values of 1.4 W m-1 K-1 at 825 K. Figure of merit values are increased for the undoped solid solutions at lower temperatures when compared to the end members due to the decreased thermal conductivity, with the y = 0.5 sample reaching zT = 1.6 × 10-3 and y = 1 reaching 2.1 × 10-3 at 700 K. The largest values of the figure of merit zT for the undoped series was found for y = 2 with zT = 2.8 × 10-3 at 700 K due to the increasing n-type Seebeck coefficient. Boltztrap calculations reveal that p-doping could yield zT values above unity at 800 K in case of ZnSnAs2, comparable with ZnSnP2.

Fluid evolution and mineralizing process of the Bawang Fe-Zn-Sn deposit, Danchi Fold-and-Thrust belt, South China

The Bawang deposit, a newly discovered Fe-Zn-Sn deposit occurred in the paleokarst in the Youjiang Basin, South China, offers an excellent opportunity to understand the ore-forming process and genesis of this unique tin mineralization, thus enriching the tin mineralization theories. Mineralogy, X-ray photoelectron spectroscopy (XPS), and laser ablation-inductively coupled plasma-mass (LA-ICP-MS) analysis were performed on sphalerite to investigate the fluid evolution and mineralizing process of the Bawang deposit. The formation of the deposit involved hydrothermal-cassiterite-sulfides and oxidation periods. The hydrothermal-cassiterite-sulfides period is dominated by the mineralization of Zn- (stage 1), Sn- (stage 2), and Sb- (stage 3) in order. Three types of sphalerite were identified in these hydrothermal stages. Mineralogical studies and spectrum data show that the massive sphalerite in stage 1 (Sp1) is euhedral coarse-grained and characterized by high Fe contents (9.67–15.69 wt%), with obvious pyrrhotite blebs, pyrite laths, stannite and/or chalcopyrite solid solutions. The sphalerite with 5.56–11.31 wt% Fe contents in stage 2 (Sp2) occurs as fine-grained, euhedral to subhedral crystals (15–50 μm) and coexists with cassiterite, arsenopyrite, and quartz. The sphalerite in stage 3 (Sp3) is characterized by low Fe content (0.59–2.99 wt%) and is generally micro-fine-grained (10–30 μm) associated with stibnite, sulfosalts, and carbonates. LA-ICP-MS analyses of sphalerite suggest that Sp1 and Sp2 have similar characteristics and are enriched in Fe, Cu, Sn, Ga, and Cd, whereas Sp3 is enriched in Sb, Pb, Ag, Bi, and Tl. The principal component analysis (PCA), boxplots, and bivariate plots of trace elements from sphalerite, combined with previous Raman spectroscopy data for fluid inclusions and H-O-Cd isotopic compositions, indicate two types of ore-forming fluids were involved in the mineralization of the Bawang deposit. The early Fe-Zn-Sn-Cu-In-rich fluids originated from granitic magma and underwent Zn- and Sn-dominated mineralization in order in a slowly cooling closed system. The later hydrothermal fluids with the addition of oil field brine were enriched in Sb, Pb, Ag, and Bi elements in the Sb-sulfosalts-carbonates stage in an open system with a drop in temperature. The mineralization process of the Bawang deposit can be concluded as follows: The early ore-forming fluids derived from an inferred concealed intrusion infilled into the paleokarst (below 350 m of the altitude) and caused the massive euhedral ferroan sphalerite (stage 1) to precipitate. The deposition of sphalerite decreased sulfur fugacity (fS2) in a slowly cooling closed system, and increased relative oxygen fugacity (fO2) which promoted cassiterite to precipitate in stage 2. The foreign hydrothermal fluids lowered the temperatures of residual ore-forming fluids due to the addition of oil field brine. Then the Pb-Sb sulfides and Pb-Sb-Ag-Bi-bearing sulfosalts (stage 3) crystallized at shallow depths (350 to 500 m of the altitude).

Three-Dimensional Distribution of Platinum Group Minerals in Natural MSS-ISS Ores From the Norilsk One Deposit, Russia

The Mt. Rudnaya MSS-ISS (monosulfide and intermediate solid solution) fine-grained ores from a NE termination of Norilsk 1 deposit were analyzed using a combination of X-ray computed micro tomography, spectral X-ray computed micro tomography and scanning electron microscopy to achieve both, 2D and 3D data. The ores consist of ISS composed of tiny lamellar intergrowths of cubanite and chalcopyrite solid solutions, which form up to 4-mm distinct globules surrounded by an ISS-MSS matrix. Our X-ray computed micro tomography results may provide 3D textural evidence of a possible natural sulfide-sulfide liquid immiscibility between Cu-rich and Cu-poor sulfide liquids that occurred before MSS and ISS were crystallized. The platinum group minerals (PGM) distribution shows that 20.6 vol% of all PGM occur in the ISS-MSS matrix and 79.4 vol% in the ISS globules. We suggest that this distributional behavior is due to the fact that the platinum group elements (PGE) cannot be dissolved in ISS, which led to the formation of the large PGM grains, which are up to 120 μm on their longest axis. The initial enrichment of ISS in PGE was controlled by differences in the partition coefficients of platinum and palladium between Cu-poor and Cu-rich liquids.

Splitting of the Chalcopyrite Polyhedron in an Isothermal Zn–Cd–Ge–As Tetrahedron

Using available fragmentary experimental data, we have constructed an isothermal subsolidus composition diagram of the Zn3As2–Cd3As2–Ge–As system and identified the phases involved in stable equilibria with a chalcopyrite solid solution. A consistent model has been proposed for the splitting of the chalcopyrite phase region into Zn1 –xCdxGeAs2 (0 ≤ x < 1) and Cd1 –yZnyGeAs2 (0 ≤ y <1) polyhedra in the Zn–Cd–Ge–As tetrahedron, and the 25 at % Ge section of the Zn–Cd–Ge–As tetrahedron has been mapped out.

Homogeneity and Primary Crystallization Polyhedra of Chalcopyrite in the Cd–Ge–Mn–As Tetrahedron

Isotherms of the T–x–y–z projection of the p–T–x–y–z phase diagram for the system Cd–Ge–Mn–As have been constructed by a topologic representation of phase states using fragmentary experimental data. In the absence of melt (below 320°C), 18 stable equilibria involving four crystalline phases were found to exist. For limited chalcopyrite solid solutions (Cd,Ge,Mn)As2, eight crystalline phases affecting its cationic composition have been isolated, namely, Cd3As2, CdAs2, GeAs, GeAs2, Ge, MnAs, MnGeAs2, and As. The (Cd,Ge,Mn)As2 homogeneity area has been shown to be a 14-vertex nonahedron, and the transformation of the (Cd,Ge,Mn)As2 polyhedron upon the appearance of melt has been considered. A model of the primary crystallization polyhedron has been presented for limited solid solutions (Cd,Ge,Mn)As2 in equilibrium with the saturated vapor.

Defect Structure and Photogenerated Carrier Loss Processes in Cu1 –x(In0.7Ga0.3)Se2 (0 ≤ x ≤ 0.30) Chalcopyrite Solid Solutions

Defect Structure and Photogenerated Carrier Loss Processes in Cu1 –x(In0.7Ga0.3)Se2 (0 ≤ x ≤ 0.30) Chalcopyrite Solid Solutions

Thermoelectric performance of Cu1−x−δAgxInTe2 diamond-like materials with a pseudocubic crystal structure

In a tetragonal chalcopyrite solid solution Cu1−xAgxInTe2 (x = 0–0.5), a pseudocubic structure is realized at x ≈ 0.2. The degenerate valence bands influence electrical transport and lattice thermal conductivity. The highest ZT of 1.24 was obtained at x = 0.2 and δ = 0.05.

Copper–zinc albite porphyry in the Hersai porphyry copper deposit, East Junggar, China: A transition between late magmatic and hydrothermal porphyry copper deposit

A 418Ma albite porphyry dike emplaced in a 429Ma granite pluton in the Hersai porphyry copper deposit (Nom, East Junggar, China) consists of euhedral and pale-orange luminescing albite phenocrysts and groundmass, zircons, blue-violet luminescing apatites and chalcopyrite–sphalerite-rich miarolitic cavities. This dike is characterized by two-domain textures presented by albites and disseminated intergranular miarolitic cavities, and by geochemical features of continental island arc and adakitic intrusions.The miarolitic cavities consist of various minerals that crystallized in the following sequence: epidote, rutile and sphalerite–chalcopyrite solid solution, titanite and K-feldspar; chalcopyrite with pyrite inclusions; and chlorite, zoisite and calcite. The miarolitic cavities exhibit magmatic to hydrothermal internal textures, such as aplitic textures presented by intergrowths of albite, epidote, rutile and sphalerite–chalcopyrite solid solution, zoning and intersertal texture, poikilitic textures, and layered chlorites. The sphalerite contains a high concentration of exsolved chalcopyrite (up to 10 vol.%). The rutiles intergrown with epidotes contain 137 to 528ppm Zr corresponding to Zr-in-rutile temperatures of 507 to 625°C, and the rutiles intergrown with sphalerite–chalcopyrite solid solutions have 381 to 420ppm Zr and Zr-in-rutile temperatures of 585 to 605°C. Mineralization temperatures of sphalerite–chalcopyrite solid solutions are possible approximately 600°C. The formation of the chalcopyrite–sphalerite-rich miarolitic cavities is related to interstitial residual sulfide-rich fluids. The copper–zinc albite porphyry may represent a copper–zinc (Cu–Zn) subtype of porphyry copper deposit that formed as a transition between late magmatic and classical hydrothermal porphyry copper deposits.

Magnetic properties of CuGa0.94Mn0.06Te2

As part of a search for new spintronic materials, we have studied the magnetic properties of the CuGa0.94Mn0.06Te2 chalcopyrite solid solution in the range 2–400 K in weak and strong magnetic fields. Magnetization isotherms, σ(H), were obtained in magnetic fields of up to 3980 kA/m. σ(T) data were collected in two ways: the sample was cooled in a magnetic field or in zero field. The experimental data were analyzed by fitting to the Langevin function. The data are adequately represented by this relation in the case when the magnetic moment of the clusters is μcl = 23.4μB and the concentrations of magnetic clusters and noninteracting Mn2+ ions are n cl = 2.4 × 1025 m−3 and n pm = 5.7 × 1025 m−3, respectively. The calculated average cluster size is d cl = 33 A, the number of Mn2+ ions per cluster is z = 21 atoms per cluster, and the magnetic moment per Mn2+ ion in the clusters is μMn = 1.1μB. This μMn value is far below the theoretical magnetic moment of the Mn2+ ion in the electronic configuration d 5(5.9μB), suggesting antiferromagnetic exchange interaction.

Experimental study of the phase equilibria in the crystallization region of the chalkopyrite solid solution

Citation: Kravchenko, T.A. (2011), Experimental study of the phase equilibria in the crystallization region of the cнalkopyrite solid solution, Vestn. Otd. nauk Zemle, 3, NZ6056, doi:10.2205/2011NZ000186. The Chalcopyrite (or intermediate) solid solution has been experimentally established in the center section of the Cu–Fe–S system at 300–800 °C [Merwin and Lombard, 1937; Yund and Kullerud, 1966; Cabri, 1973; Barton, 1973; Lihachev, 1973; Sugaki, et. al., 1975; Vaughan and Craig, 1978; 1997; Tsujmura and Kitakaze, 2004]. The phase equilibria concepts of the chalcopyrite solid solution crystallization products at low temperatures are not clear and contradictory, since they are based on the results of investigating the natural phase associations and the extrapolation of the separate experimental data to the low temperatures region [Vaughan and Craig, 1978; 1997]. The phase associations of the center section of the system Cu–Fe–S: 50 at.% S, Cu/Fe = 1.22–0.25, 47 at.% S, Cu/Fe = 1.12–0.63 and 45 at.% S, Cu/Fe = 1.44–0.69 have been synthesized to determine the phase equilibria in the crystallization region of the chalcopyrite solid solution. The scheme of the phase relations in the central Сu–Fe–S system (marked with the dashed lines in the figure below) considering the results of the most complete experimental study of phases from the region of the chalcopyrite solid solution [Cabri, 1973] has been used as the basis for the selection of the initial compositions of the synthesized samples. The synthesis has been carried out in the vacuum quartz ampoules using the melt cooling method from 1150– 1100 °C to the room temperature and the following annealing at 600 and 800 °C. The synthesized samples have been studied using the optical microscope and the X-ray diffraction methods. The obtained results are represented in the figure and in the table below. Talnakhitе Cu9Fe8S16 has been synthesized in samples 1 and 8: 50 at.% S, Cu/Fe = 1.22 and 47 at.% S, Cu/Fe = 1.12 in the association with chalcopyrite and bornite, whereas in sample 5а: 50 ат.% S, Cu/Fe = 0.54 it has been synthesized in the association with cubanite. Cubanite CuFe2S (cubic fcc) has been synthesized in samples 3–7, which original compositions are located on the chalcopyrite-cubanite-pyrrhotite line (fig.). In samples 3–5a: 50 at.% S, Cu/Fe = 0.82–0.54 cubanite has been synthesized in the association with the tetragonal chalcopyrite, in sample 6: 50 at.% S, Cu/Fe = 0.43 — in the association with pyrrhotite and haycockite, and in sample 7: 50 at.% S, Cu/Fe = 0.25 — in the association with pyrrhotite. It has been established that cubanite CuFe2S3 enriched by iron (Cu/Fe  0.5), is crystallized in the associations with haycockite and pyrrhotite, while being enriched by copper (Cu/Fe  0.5) it is crystallized in the associations with talnakhitе or chalcopyrite (samples 5 and 5a), depending on the cooling regime. Mooihoekite Cu9Fe9S16 has been synthesized in samples 9 and 12: 47 at.% S, Cu /Fe = 0.93 and 45 at.% S, Cu/Fe = 1.44 in the association with bornite, regardless of the synthesis regime. As opposed to cubanite and talnakhitе, which are crystallized in the form of the exsolution texture with chalcopyrite, mooihoekite is the easily diagnosed homogeneous phase. Haycockite Cu4Fe5S8 (phase of the haycockite composition with the cubic pc structure) has been synthesized in sample 10: 47 at.% S, Cu/Fe = 0.77 and 13: 45 at.% S, Cu/Fe = 1.20 in the association with bornite, in sample 11: 47 at.% S Of cu/Fe = 0.63 and 14–15: 45 at.% S, Cu/Fe = 1–0.83 in the association with bornite and pyrrhotine, and also in the above sample 6 in the association with pyrrhotite and cubanite enriched by iron. Same as mooihoekite, haycockite is diagnosed easily.

Superparamagnetism in Mn-doped CuGaTe2

We have established conditions for the preparation of CuGaTe2〈Mn〉 chalcopyrite solid solutions containing manganese on one or two cation sites, which are expected to be suitable for spintronic applications. Models for the formation of the solid solutions have been proposed, and the cation and valence distributions have been inferred from experimental data. The magnetic and electrical properties of CuGaTe2〈Mn〉 can be accounted for by the presence of Mn2+-containing superparamagnetic clusters.

Evaluation of band gaps in CuGa(SxSe1−x )2 solid solutions from calculated total densities of states

The local partial and total densities of states in CuGa(SxSe1−x)2 (x=0, 0.17, 0.33, 0.50, 0.67, 0.83, and 1.0) solid solutions are calculated by the local coherent potential method within the virtual crystal approximation. The lattice parameters of the chalcopyrite solid solutions under investigation are determined in the framework of the Jaffe-Zunger theory with the use of the Pauling tetrahedral radii. It is revealed that the band gap E g linearly depends on the sulfur concentration x in the anionic sublattice. This result is in agreement with the experimental data, but the theoretical band gaps E g are found to be approximately 0.5 eV less than the experimental values.

Co2+ in Defect Chalcopyrite Solid Solutions and Valence Band Offest in Defect Chalcopyrite Solid Solutions

The purpose of this presentation is to report the valence band offset assignment in Zn1-xCdxGa2Se4/ZnGa2Se4, Zn1-xHgxGa2Se4/ZnGa2Se4, Cd1-xHgxGa2Se4/CdGa2Se4, HgGa2-xInxSe4/HgGa2Se4 heterojunctions using transition metal energy level in the gap as a reference. We used the energy level of Co2+ in defect chalcopyrite solid solutions to evaluate the valence band offset. The composition dependent energy gaps Eg(x) are presented along with EgCo2+(x), i.e., energy gaps of cobalt doped solid solutions. The valence band offset is expressed as the difference in energy gap between pure and cobalt doped solid solutions.

Sintered quaternary and pentenary chalcopyrite solid solutions for solar cell applications

Large grain quaternary and pentenary chalcopyrite solid solutions with composition suitable for solar cell applications were obtained by means of the sintering technique. Electrical properties as a function of sintering processes (temperature and time of thermal treatments under controlled atmospheres) are discussed. The mobility values are related to the grain size while the resisxivity values and the conductivity type are mainly affected by doping elements (Se and Cd).

Bulk compositions of intimate intergrowths of chalcopyrite and sphalerite and their genetic implications

To determine the bulk chemical compositions of chalcopyrite containing starlike sphalerite and sphalerite including dotlike chalcopyrite, specimens from various types of ore deposits in Japan were used for modal and electron microprobe analyses. According to the analytical results, most of the measured zinc contents in chalcopyrite containing starlike sphalerite are less than 0.8 at%, corresponding to the maximum solubility of zinc in chalcopyrite as determined experimentally at 400°C. However, specimens from the Maruyama deposit in the Tsumo mine contain 1.2–1.4 at% Zn, which are within the solubility limit of an intermediate solid solution (ISS) above 400°C. It is therefore concluded that starlike sphalerite in chalcopyrite are exsolution products derived from primary chalcopyrite solid solution and/or zincic ISS. Measured copper contents in sphalerite including dotlike chalcopyrite yield considerably higher values, i.e., 1.5–6.0 at%, which exceed the solubility limits of copper in sphalerite solid solution as determined experimentally. This result suggests that not all the chalcopyrite dots were exsolved from sphalerite, but that most of them are the product of some other mechanisms.

Melt growth and some properties of Cu xAg 1− xInSe 2 and CuIn yGa 1−ySe 2 chalcopyrite solid solution crystals

Crystals of Cu x Ag 1− x InSe 2 and CuIn yGa 1−ySe 2 have been grown from the melt by a liquid-encapsulated Bridgman-Stockbarger method after in situ synthesis from the elements. Values of x and y equal to approximately 0, 0.25, 0.5, 0.75, 0.9 and 1.0 were chosen for the elemental starting compositions. Electron microprobe measurements at the 15%-fraction-solidified point for each crystal indicated only weak segregation effects. p-Type conductivity was observed in all cases except x = 0 and x = 0.25.

Crystal growth of quaternary and pentanary chalcopyrite alloy single crystals for solar cell applications

The growth of CuInSe 2(1-y)Te 2y, CuGaSe 2(1-y)Te 2y and CuIn 1−xGa xSe 2(1-y)Te 2y single crystals by chemical vapor transport technique in a closed tube, using iodine as a transport agent, is reported. Stringfellow's a-priori method is used in order to determine the interaction coefficients and the upper critical temperatures of pseudoternary chalcopyrite solid solutions. Resistivity and carrier mobility were determined by resistivity and Hall effect measurements using Van der Pauw method: all samples present p-type conductivity; the materials considered here have a large spread in the resistivity values.

Solid solution formation in chalcopyrite systems of the type AgIn X2Ag MIIIX 2 where M = Al, Ga, and X = S,Se

Previous ( 1) work on ternary chalcopyrite solid solution formation has shown that the difference in end point axial ratios ( Δc a ) is an important factor in determining the extent of mutual solubility. It was concluded that when Δc a > 0.13 complete solid solubility will not occur. In this work it is shown that complete solid solution formation in the systems AgAlS 2AgInS 2 ( Δc a = 0.111 ), AgGaS 2AgInS 2 ( Δc a = 0.11 ) and AgAlSe 2AgInSe 2 ( Δc a = 0.112 ) does occur. This shows that the value of Δc a = 0.13 as an upper limit for solid solution formation can be approached closely.

Paragenetic relations of some Cu-Fe-Sn-Sulfides in the Mangualde pegmatitie, North Portugal

The textures of chalcopyrite from the Mangualde pegmatite suggest: a) myrmekitic intergrowths of chalcopyrite and complex stannite-kesterite-hexastannite inclusions formed by reactions involving: 1, eutectoid unmixing of Sn-Zn-bearing chalcopyrite solid solution into chalcopyrite and Zn-bearing stannite, 2, formation of hexastannite by reaction of the stannite with chalcopyrite, whereby kesterite formed as an intermediate product; b) chalcopyrite-hexastannite myrmekites crystallized as cotectic precipitates from liquid; hexastannite was partly replaced and rimmed by mawsonite during subsequent cotectic crystallization of chalcopyrite-mawsonite myrmekites; c) stannite inclusions in cubanite-bearing chalcopyrite formed by exsolution; d) in bornite-rich samples bornite and hexastannite crystallized before chalcopyrite. Phase relations in the pseudo-ternary cubanite-stannite-bornite Zn-bearing system are depicted; the association bornite-stannite is incompatible at lower temperatures, as below about 500 °C hexastannite and mawsonite intervene as intermediate compounds.

Cu-Fe-S系鉱物の合成実験による研究 (第1報)

The phase relations in the system Cu-Fe-S, especially the one among chalcopyrite, cubanite and pyrrhotite, were studie at temperatures of 600°, 700° and 800°C by synthesis using the rigid silica glass tube method.The total composition of samples was selected as it ranges on the line which connects CuFeS2 and FeS.Electron probe microanalysis was applied for the determination of the composition of synthetic products, especially for that of the phase boundaries of chalcopyrite and pyrrhotite solid solutions. The following results were obtained.(1) The complete solid solution between chalcopyrite and pyrrhotite would not be formed even above 800° at the present experimental condition, because the region of pyrrhotite solid solution extends to the sulfer-rich direction while that of chalcopyrite solid solution retreats to the copper-rich side at temperatures above 600°.(2) The most iron-rich end of the chalcopyrite solid solution shifts from the slightly iron-rich composition to the iron-poor one than cubanite when the tethperature of synthesis rises from 600° to 800°, though the boundary of the region was unable to determine precisely by EPMA.(3) Pyrrhotite can contain Cu approximately 2.5 wt.% at 600°C, 4% at 700°C and 6% at 800°C.(4) Some causes of error at the analysis of composition by EPMA are discussed briefly.